Unfortunately, while the TSA lists 68 airports with 385 advanced scanners,
they don't document which type of scanner is used at each of those airports.
An article
on FlyerTalk
provides most of the details which are shown on the map below:

blue = millimeter wave

red = backscatter X-ray

black = unknown

In addition to the 48 contiguous states shown on the map, three other US
airports have these scanners:

Information on this site may not be accurate or current and is not valid for flight planning or navigation. No warranty of fitness for any purpose is made or implied. Flight planning and navigation should only be done using official charts.